SLASEE2 February 2018 DAC8771
PRODUCTION DATA.
The DAC8771 consists of a resistor-string digital-to-analog converter (DAC) followed by buffer amplifiers. The output of the buffer drives the current output stage and the voltage output amplifier. The resistor-string section is simply a string of resistors, each of value R, from REFIN to GND, as Functional Block Diagram illustrates. This type of architecture ensures DAC monotonicity. The 16-bit binary digital code loaded to the DAC register determines at which node on the string the voltage is tapped off before being fed into the output amplifier. The current output stage converts the output from the string to current using a precision current source. The voltage output provides a voltage output to the external load. When the current output stage is disabled the IOUT pin is Hi-Z. When the voltage output stage is disabled, the output impedance is controlled by the POC bit, by default set to 30 kΩ. After power-on, both output stages are disabled. The DAC8771 also contains a Buck-Boost converter which can be used to generate the power supply for the current output stage and voltage output amplifier.